Chemical feeder and saturator.



J. G. W. GRETH. 4 GHBMICAL FEEDER AND SATURATOR.

APPLIOATION FILED AUG-.12, 1907.

7'0 SEWER 996,923; Patented 15 4,1911.

' to use a saturating tank v I have therefore UNITED STATES PATENToFFioE.

JOHN C. W. GRE'IH, PITTSBURG, PEITNSYLVANIA, ASSIGNOR TO WM. 1B. SCAIFE86 SONS COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEWJERSEY.

CHEMICAL FEEDER AND SATURATOB.

purifying apparatus although it has various.

other applications as will hereafter be obvious, and its primary objectsare to handle.

the chemicals such as milk of lime and efiiciently introduce them intothe water purifying system without passing them through a pump. p

. Other objects are to provide a continuously operating displacementdevice for gradually introducing a definite amount of chemical, toprovide for efficient saturating of the chemical and to provide meansfor introducing the chemical into the saturating tank at the bottom andagainst pressure.

These objects and various other advantages to hereinafter appear areattained by the devices illustrated in the accompanying drawings, wherethe invention is shown as applied to a water purifying system andwherein,-

Figure 1 is a diagrammatic elevation of parts of a water purifying plantincluding my invention. Fig. 2 is a horizontal crosssection of asaturating tank. Fig. 3 is a central vertical section of thedisplacement introducer and Fig. 4 is a horizontal section of the same.

In the building of large water purifying plants where reaction andsettling tanks are built some 50 to 80 feet high, it is advisable ofapproximately the same height, and it obviously is a decided problemhow,to introduce the reaction chemicals at the 'bottom and under suchheavy head. It is practically impossible to use a pump for suchmaterials as milk of lime because the grit soon destroys the machinery.It is obviously also highly objectionable to work with mixing devices onthe top of said tanks, and it has also been pointed out in some of myprior patents that the efliciency of the chemicals is much. increased byintroducingthem under head. devised the present means of introducingm'lk of lime into a saturating tank and there saturating it in aneflicient manner for use in the reaction vessels.

Specification of Letters Patent.

Patented July 4, 1911.

Application filed August 12, 1907. Serial No. 388,139.

is provided any con-. slaking vessel 5 for the In Fig. 1, there venientmixing and lime and from this through valve 6 and pipe 7 into thedisplacement introducer 8, from whence it is carried by the pipe 9 alongwith the raw Water taken from the supply pipe 10, 10", 10 into thesaturating device 11, and from this the water afterward goes to thereaction tank for use as will be understood. The rest of the apparatusneed not be described since my invention resides in means for handlingthe lime and mixing it in the Water to make a saturated solution of limehydrate.

As shown in Fig. 1 especially, the displacement vessel 8 first receivesa full charge of milk of lime flowing in by the pipe 7, the air in tank8 meanwhile escaping through a small pipe 12 as shown in Fig. 3. Afterthe displacement tank 8 is completely filled with milk of lime, thevalve 6 on the pipe from the mixer is closed and thevalve 13 on the pipe10" is opened and the raw water flows in .through pipe 10 as indicatedand gradually displaces and carries along with it the charge of milk oflime, carried into the saturator through the pipe 9. At the bottom ofthe tank 8 I provide a baffle plate 14 which is supported on' legs 15over the mouth of the pipe 10' and the inrushing water will thus becaused to take a rolling motion and efficiently carry out all the limefrom the bottom of the tank, so that eventually every particle of limewill be carried out from the vessel 8. The milk of lime being carriedalong with the raw Water through the pipe 9, enters into the vessel 11,first into central cylinder 16, passing directly upward and over the topedges 0 this cylinder which being inclosed by the sides of intermediatecylinder 18, it is caused to again flow downward under the edges of thispartition 18 and finally upward again between it and the wall of theoutside tank 11. The clear lime hydrate solution thence flows over theannular weir 19 and through the feed pipe 20 to the reaction tank.

The various partitions and parts of the saturating tank- 11 aresupported upon beams 21 and underneath these is a conical shaped bottom22 which communicates directly with the pipe 23. This latter by way ofvalveEZEl is connected with the sewer for the purpose of blowing ofi theprecipiwhich is thus the milk of lime flows tates out of the saturatorwhen desired,

bemg understood that CaCO Mg.(OH)

etc., precipitated by the lime are insoluble. Since it takes some timefor the milk of lime to be changed to saturated lime water, it isevident that some particles of the lime still unused, will be carried upfrom cylinder 16 and down with these pre cipitates to the bottom.Therefore I use a small pipe 24 with a Valve 25, connected to the pipe23 and communicating directly 3 with the main supply pipe behind theupward so that no is closed andvalves 9" c and water flows in throughpipe 10 and out connections to 10 and to the reaction tank. There isthus supplied a continuous stream of raw water at the extreme bottom ofthe saturating tank and this besides preventing any choking up of thepipe 23 by sediment, efl'ectually utilizes whatever parts of the limemay be left unused and precipitated in the saturator.

The stop cock or valve 28 on the ipe 10 is set with an opening properlydesigned to divert such an amount of water through the pipe 10 as tocause introduction of the proper amount of saturated solution of limehydrate to react with the impurities in the raw water introduced throughthe main 27 The pipe 24 and also the by-pass pipe 29 around thedisplacement vessel, are independent of the latter, and it will be plainthat while the displacement vessel 8 is being refilled, raw water maystill be supplied to the tank 11 to dissolve the excess of lime, whichof course always remains therein. hus a continuous flow of saturatedsolution of lime water is always kept flowing out of the saturating'tankand into the re- I action tank.

It will be seen from that in operation the with milk of lime,

the above description tank 8 is first filled whereupon the valve 6 and13 are opened through pipe 9 to the saturator carrying with it the milkof lime, and in the saturating tank a. true-lime hydrate solution ismade by theextended .vertical reverse flow and clear solution taken offby overflow at the top to the reaction tank. When the dlsplacement tank8 is empty of lime and a new charge is desired, valves 9* and 13 areclosed and valve 30 opened, whereupon the flow of water will continue inthe saturator and all the lime is reduced to a hydrate solution byreason of this double current through ipes 9 and 23, any sedimentprecipitated from chamber 18 on the downflow bein picked up anddissolved and utilized by the current from pipe 23; that is whlle thistank provides a main reversed, yet the extreme bottom-of the has acontinuously tank flowing current of water sediment can collect, thepipes cannot be choked and all the lime is utilized. It will be notedthat the displacecurrent which is vertically ment vessel 8 and thesaturating vessel 11 really form parts of one continuous saturatingdevice, and by the arrangement above described, including the constantlyflowing by-pass pipe 24, the flow of saturated solution to the reactiontank T is continuous even though the displacement vessel operatesintermittently. The filling of the displacement vessel 8 ordinarilytakes but a few minutes, while the charge may be introduced into thesystem continuously during a period of ten hours or at whatever ratedesired.

The advantage of having the mixing vessel 5 and all the valves on theground at the base of the saturating and reaction towers, will bereadily apparent, and in short the introduction of the lime into thesystem is accomplished in a thoroughly accurate and eflicient andentirely controllable manner.

f course any other chemical having similar properties to that describedcan be used by the same apparatus and it will also be evident to thoseskilled in the art that there are various other uses for the devicesdescribed.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is the following:

'1. In water purifying apparatus, the combination with a water supplareagent supply, and a reaction tank, of a pipe direct from the watersupply to the reaction tank, a saturator and closed connection from thewater su ply to the saturator, a displacement feeding vessel andconnections to fill it with the reagent and empty it into thesaturatoryincluding a closed pipe from the water supply to. thedisplacement vessel, whereby a deviated proportional part of the watersupply may displace in said vessel and discharge into the saturator anequal amount of the reagent.

2. In water purifying apparatus, the combination with a water supply, areaction "tank and a chemical supply, of a mam'feed pipe from the watersupply direct to the reaction tank, a branch pipe from said supplydirect to the saturator, a displacement feeding device for the reagentoperated by part of the water supply, and a by-pass around thedisplacement vessel.

3. In water purifying apparatus, the combination with a reaction tankand water supply, of a saturating vessel having a continuously flowingbranch from the water supply thereto, a reagent supply and a reagentfeeder operated by displacement and connected to the saturator,comprising a closed vessel with a reagent inlet at the top and a waterinlet at its extreme bottom and a second or by-pass pipe shunted aroundthe feeder direct to the saturator, substantially as described.

4. The combinatlon of a saturating tank,

around the displacement vessel, and a supplementary by-pass directlyfrom the mam supply to the extreme bottom of the saturating tank.

5. In water purifying apparatus, the combination with a saturating tank,a reagent supply, and a reagent feeder operated by a deviated part ofthe Water supply, of a bypass around the feed, and a supplementaryby-pass directly from the main supply to the saturating tank, whereby tocontinue a water-flow thereto when the feeder is not in operation.

6. In water purifying apparatus, a saturating tank having partitions tocause reverse vertical flow therethrough, a conical bottom under allsaid partitions, means to introduce chemicals under head into one of thecompartments, and a. supplementary water supply pipe connected to theapex of the conical bottom, whereby to stir up the sediment in the tank,substantially as de- I scribed. 7. In water purifying apparatus, asaturator comprising means to introduce limeinto a central compartmentand circulate it radially outward and in reverse vertical currents, andmeans for introducing raw water at the extreme bottom of the tank toutilize the undissolved lime, substantially as described.

' In testimony whereof, I have hereunto signedmy name in the presence ofthe two subscribed witnesses.

JOHN C. W. GRETH.

Witnesses: I

F. W. H. CLAY, CHAS. S. LEPLEY.

